There are approximately two million children with ankle injuries who visit emergency departments in Canada and the United States each year. X-rays are currently ordered for about 95 per cent of these children, however only 12 per cent of those actually reveal a fracture.

In a new study, researchers from The Hospital for Sick Children (SickKids) found a 23 per cent decrease in the number of ankle X-rays in paediatric emergency departments that used a clinical decision tool called the Low Risk Ankle Rule. This reduction in radiographs was also the primary driver for the significant reduction in health-care costs, averaging $37 per patient.

The study was published online July 14 in Annals of Emergency Medicine.

The Low Risk Ankle Rule helps physicians determine if an ankle injury is low risk depending on where tenderness and swelling is located in the ankle. In emergency departments where the Low Risk Ankle Rule has been implemented, there were also no significant differences in the frequency of missed clinically important fractures.

"Our findings show that X-rays are unnecessary for most children's ankle injuries, and they needlessly expose them to radiation," says lead author Dr. Kathy Boutis, Staff Physician, Paediatric Emergency Medicine and Senior Associate Scientist, Child Health Evaluative Sciences at SickKids. "Widespread use of the Low Risk Ankle Rule could lead to a reduction in unnecessary radiation exposure through fewer X-rays and could also lower health-care costs."

Researchers also found that the application of the rule in emergency departments significantly and safely decreased the rate of X-rays without a change in doctor or patient satisfaction. The lower rates of X-ray use and fewer follow-up visits to the orthopaedic surgeon were the main reasons for the reduction in health-care costs. The cost analysis also determined that there was no increased use of health-care resources after discharge for patients that were assessed using the Low Risk Ankle Rule.